Most scaffolding systems include scaffold legs that are connected in an end to end manner to form an upright column. Typically, a spigot-type arrangement is used to connect a lower scaffold leg to an upper scaffold leg. In some scaffolding systems, the spigot is an integral part of the top portion of the scaffold leg often formed by seeming to reduce the diameter at the end, and the bottom portion of the scaffold leg is slightly enlarged or bell mouthed to receive the spigot. Other scaffolding systems use a separate spigot member that is inserted in a lower end of an upper scaffold leg, and a lower portion of the spigot is inserted in the end of the lower scaffold leg. Typically, the spigot is attached by a removable gravity lock pin, such as a pigtail pin, to the lower portion of the upper scaffold leg. A clevis pin may be used to secure the spigot to the upper portion of a scaffold leg and scaffold legs abut end to end.
With independent spigot arrangements as well as the integral spigot, there is often a requirement to provide a positive lock of the scaffold legs to each other. In case of the integral spigot arrangement, this is typically a gravity lock pin, such as a pigtail pin, inserted through a port in the upper scaffold leg, and through an aligned port in the spigot portion such that the pin passes from one side of the scaffold leg to the other side. This gravity lock pin forms a positive lock of the scaffold legs one to the other. In the case of an independent spigot, a clevis pin may be used to mechanically secure a bottom portion of the spigot to the lower scaffold leg, and a gravity lock pin typically secures the upper scaffold leg to the upper portion of the spigot.
In some scaffold applications it is desirable to have a number of speciality components that can be inserted into the top or bottom of the scaffold leg. To satisfy these applications, an independent spigot is preferred as it allows more flexibility with respect to the connection of speciality components.
Although scaffolding systems are designed to allow mechanical securement of the scaffold legs one to the other (by bolts for example), this procedure is not always completed, creating a significant safety risk. Safety inspectors often shut down a job site until such safety procedures are complied with. It is desirable to provide a system where the securement of stacked scaffold legs is simplified.